A resume gets about half a minute on first read. The person reading it wants three answers fast: what you do, how well you did it, and whether it matches what they need. Everything below serves those three.
Contact details at the top, a two-line summary, then experience with bullet points, skills, and education. One page if you have under ten years of experience, two at most after that. Nobody reads page three.
"Responsible for customer support" says nothing. "Cut average response time from 2 days to 4 hours" gets an interview. Every bullet should carry a number you can defend: money saved, time cut, people managed, volume handled. If a bullet has no result, rewrite it or delete it.
Read the job ad and mirror its words. If they ask for "project management", do not write "led initiatives". Screeners - human and software - look for the words in the ad. Ten tailored resumes beat fifty identical ones.
Photo, date of birth, full home address, marital status, and "references available upon request". All of them waste space or invite bias, and none of them get you hired.
Read it out loud once; typos you skim past on screen become obvious. Save it as a PDF with a boring file name like "jane-cohen-resume.pdf". Skip the fancy two-column template with icons - some tracking systems mangle it into nonsense.
General guidance, not career counseling. Norms differ by field and country.